Fungal Pathogens Microbes and Society

Meningitis Cryptococcus neoformans causes swelling in the membranous covering of the spinal cord. Cryptococcus neoformans causes swelling in the membranous covering of the spinal cord. Organism is found in pigeon droppings which dry out and are carried in the wind or eucalyptus trees and decaying wood forming hollows in living trees Organism is found in pigeon droppings which dry out and are carried in the wind or eucalyptus trees and decaying wood forming hollows in living trees Organism is a fungus with a capsule that helps it avoid the immune system. Organism is a fungus with a capsule that helps it avoid the immune system. Why doesn’t everybody get cryptococcosis? Why doesn’t everybody get cryptococcosis?

Why isn’t everyone infected? Because the immune system handles the yeast normally. This is a problem of the immunocompromised, especially AIDS patients. Because the immune system handles the yeast normally. This is a problem of the immunocompromised, especially AIDS patients.

What anatomical sites are infected with this fungus Central Nervous System (CNS) and lungs Central Nervous System (CNS) and lungs Remember, we breathe it in first! Can cause pulmonary problems too. Remember, we breathe it in first! Can cause pulmonary problems too.

Other Eukaryotic Pathogens that Cause Meningitis Histoplasma (another bird dropping fungus) Histoplasma (another bird dropping fungus) Coccidioides (soil fungus) Coccidioides (soil fungus) Toxoplasma (protozoa found in cat feces and/or undercooked meat) Toxoplasma (protozoa found in cat feces and/or undercooked meat) Naegleria fowleri (amoeba that caused those 3 boys to die in Florida) Naegleria fowleri (amoeba that caused those 3 boys to die in Florida) Blastomyces dermititidis (another bird dropping fungus) Blastomyces dermititidis (another bird dropping fungus)

Some Prokaryotic Organisms that cause Meningitis Bacterial Bacterial Haemophilus influenzae type b, Haemophilus influenzae type b, Neisseria meningitidis, Neisseria meningitidis, Streptococcus pneumoniae Streptococcus pneumoniae Bacteria are spread by close contact (like in dorms!) Can be treated with antibiotics Can be VERY serious, leading to brain damage and/or death There is a vaccine!

Viral Meningitis Many different viruses cause viral meningitis Many different viruses cause viral meningitis Makes individuals very ill, but rarely kills Makes individuals very ill, but rarely kills Nicknamed “aseptic meningitis” Nicknamed “aseptic meningitis” No treatment, but usually clears up on its own No treatment, but usually clears up on its own More common in summer and fall and is transmitted through direct contact of respiratory secretions More common in summer and fall and is transmitted through direct contact of respiratory secretions Need to determine which meningitis you have so you can get proper treatment Need to determine which meningitis you have so you can get proper treatment

Fingernail Fungus Wide variety of dermatophytes cause this condition Wide variety of dermatophytes cause this condition Condition is called onychomycosis Condition is called onychomycosis Organisms thrive on keratinized tissue Organisms thrive on keratinized tissue VERY common problem (as seen by TV ads) VERY common problem (as seen by TV ads)

Definitive Diagnosis Nail scraping can identify if it is fungal Nail scraping can identify if it is fungal Can also cause scalp or skin problems Can also cause scalp or skin problems

Treatment for Fingernail Dermatophytes Best to see a physician to rule out metabolic conditions or chronic diseases. Best to see a physician to rule out metabolic conditions or chronic diseases. Topical treatments such as itraconazole or terbinafine may or may not be effective and may take as little as 3 months and as long as 12 months to treat. Topical treatments such as itraconazole or terbinafine may or may not be effective and may take as little as 3 months and as long as 12 months to treat. Even the super expensive oral treatments are not 100% Even the super expensive oral treatments are not 100% Diligence and patience is required! Diligence and patience is required!

Common Dermatophyte Conditions Athlete’s feet Athlete’s feet Jock Itch Jock Itch Ring Worm Ring Worm All these surface All these surface mycoses (mycology = study of fungus) are capable of digesting keratin and are stubborn when treating.

Ringworm is not a WORM! Usually has a defined round edge and is scaly Usually has a defined round edge and is scaly Can treat with athlete’s foot medicine Can treat with athlete’s foot medicine Treat for 1 week after lesion has gone away Treat for 1 week after lesion has gone away Ringworm is contagious! Ringworm is contagious!

Yeast Infection Caused by the yeast Candida albicans that is normally found in women during their childbearing years. Caused by the yeast Candida albicans that is normally found in women during their childbearing years. Normally the lactobacilli (lactic acid producing bacteria) keep the level of Candida low Normally the lactobacilli (lactic acid producing bacteria) keep the level of Candida low Candida are “opportunistic” pathogens Candida are “opportunistic” pathogens

Predisposition Factors for Yeast Infections Things that change the pH of the vagina such as birth control pills, pregancy, use of broad spectrum antibiotics, diabetes mellitus or sometimes it is sexually transmitted. Things that change the pH of the vagina such as birth control pills, pregancy, use of broad spectrum antibiotics, diabetes mellitus or sometimes it is sexually transmitted. HIV infected individuals usually have frequent yeast infections HIV infected individuals usually have frequent yeast infections (both vaginally or orally as in thrush)

Treatment Oral and vaginal over the counter treatments are effective Oral and vaginal over the counter treatments are effective Recurrent infections should be seen by a physician to rule of HIV or other immunocompromised complications Recurrent infections should be seen by a physician to rule of HIV or other immunocompromised complications Yeast infections rarely cause serious pathology, though in immunocompromised individuals they could lead to a fatal bloodstream infection Yeast infections rarely cause serious pathology, though in immunocompromised individuals they could lead to a fatal bloodstream infection

Prevention If taking oral antibiotics you may also treat prophylatically for yeast infection If taking oral antibiotics you may also treat prophylatically for yeast infection Eat a lot of yogurt of other lactobacillus (live) infused foods. Eat a lot of yogurt of other lactobacillus (live) infused foods.